The present disclosure describes systems and techniques relating to effectively increasing a command queue length for accessing storage, such as by increasing the Queuing Depth (Q-Depth) of Serial Advanced Technology Attachment (SATA) Native Command Queuing (NCQ) Commands.
Many electronic devices include embedded systems to control the operation of the underlying devices and to provide enhanced functionality and operational flexibility. Typically, non-volatile memory is included as a portion of the embedded system to store operating system program code, issued commands and critical data for operating the embedded system. Some embedded systems use solid state memory as non-volatile memory (e.g., electrically Erasable Read Only Memory (EEPROM)). Solid state memory may be used to accelerate applications to increase data access time, and may be advantageously programmed or re-programmed to provide non-volatile storage of information.
In a computer system, a host bus adapter can connect a host system (e.g., a computer) to other network and storage devices (e.g., a hard disk drive, a solid state drive, an optical disk drive, etc.). Serial Advanced Technology Attachment (SATA) is an interface protocol used to control transfer of data and information from a host to a storage device. Native command queuing is an extension of the SATA protocol allowing a storage device to internally optimize the order in which received read and write commands are executed. Native command queuing protocols typically have a maximum queue length. Command consolidation is possible for sequential commands where the Logical Block Address values are adjacent. That is, sequential commands with adjacent LBAs can be combined into a single command by using the LBA value of the first command and setting a data transfer count to be the sum of the transfer count for the sequential commands.